What's going on here?
 

I'm just trying to turn on my car and it's doing this weird thing. Is it the battery? It is a new (from May 2020) Optima Yellow top.

https://photos.app.goo.gl/4Po3W8nfSXyiQAsc9

Similar thing happened to me before on a different car.

Make sure battery terminal connection is good, that the connection is slid all the way down. When it happened to me, even though it looked and felt secured, it wasn’t all the way down (due to the little anti-corrosion pad).

Yea I know, makes next to no sense. Clear metal on metal contact, but it kept happening to me at the time. It was right after I changed battery.

Bad cable connections or bad battery!

In the video your voltage gauge is showing 10 volts.
That’s not enough. Has the car been sitting for a while?
Maybe you accidentally left a dome light on?

Yes, I measured with a multimeter and the battery reads 10.6 Volts, way too low. Car has been sitting a little longer than a week, and no I didn't leave anything on as far as I know. I checked with multimeter again and got a drawing of 1mA when the car was turned off. Not sure what the normal drawing for off car is.

I have ordered a CTEK 7002 (battery tender) from amazon which I plan to use, see if the battery reacts. I tried to jump start it with my other car but it didn't work. If the battery tender doesn't work I guess I will go for the battery warranty (3 years).